Intelligent decisions

Fri, 30 Oct 2009

If we make the right decisions now about how to adapt to climate change, we can restore and even enhance biodiversity, says Robert Watson.

Photo: Andrea Molinari

When biodiversity is mentioned in the context of climate change, it is usually in reference to the devastating effect that our changing climate will have on the species that make up life on our planet as we know it. From the Millennium Ecosystem Assessment to the Convention on Biological Diversity’s Ad-hocTechnical Expert Group on climate change and biodiversity, barely a week goes by without a new piece of research showing how a warmer environment will harm biodiversity.

Yet it’s becoming increasingly clear that this isn’t the whole story: That as we come to terms with the changes we need to make in order to adapt to a changing climate, the consequences for biodiversity are much less straightforward than we might have originally thought.

To begin with, the things we do to adapt to the adverse impacts of climate change could have positive as well as negative outcomes for biodiversity and ecosystem services. The balance will vary from species to species and from ecosystem to ecosystem, but will largely depend upon the precise approach taken and the way in which such strategies are implemented. In most cases though, it should be possible to reduce negative impacts and indeed increase positive impacts, minimizing tradeoffs and threats to biodiversity. For example, adaptation activities can restore fragmented or damaged ecosystems and help re-establish critical processes such as water flow or pollination to maintain ecosystem functions. Far from being a hopeless case then, looking at adaptation from this perspective, it is possible to see it as an opportunity to do our best to enhance biodiversity.

Biodiversity is not just a bystander in our changing climate though—it also has a vital role to play in helping us adapt to a changing climate. For instance, coastal ecosystems can help reduce the risk of flooding from storm surges and a diverse agricultural landscape can support productivity under changing climate conditions. Rather than thinking about building sea walls or developing new crops that grow under different conditions, making use of these natural ecosystems as part of an adaptation strategy may prove to be more cost effective, and offer genuine spin-off benefits to the environment, as well as social, economic and cultural benefits to local communities. They may also be more accessible to rural or poor communities than approaches based on hard infrastructure and engineering.

It will be important however to remember that the ecosystems that we will be relying upon to help us cope with climate change in these situations are themselves already under great stress from climate change. If we are to rely on them more, we will need to think about how we can increase their capacity to adapt so that they aren’t forced towards unacceptable environmental limits or even to dangerous thresholds.To do this, we should be aiming to reduce any environmental stress that isn’t related to climate change such as habitat loss and fragmentation, presence of invasive species or lack of pollination insects. We should also adopt conservation and sustainable use practices to help improve the resilience of ecosystems further.

Such an approach to adaptation will not be without risks or consequences—we will still need to consider the risks, long-term implications and full impacts of such an approach as fully as we would with any other adaptation plans. There will also be trade-offs. An ecosystem- based approach to adaptation would mean managing ecosystems to provide particular services over others—giving priority to ecosystems and species of particular ecological, social or economic importance.

Alongside understanding the relationships between different species, ecosystems and services, accounting for the value of biodiversity and the ecosystem it supports will be vital too if we are to cope with climate change and enhance our natural environment. Ecosystem services contribute to the economy by providing goods (such as food) that can be bought and sold, and services (such as clean water) which would have costs if they were to be provided in another way. Since they’re usually treated as externalities by economists, their true value is rarely reflected in decision making.Many methodologies have been developed to estimate the market and non-market value of ecosystem services more effectively though. Making use of these, in frameworks such as the ecosystem approach being developed and implemented by the UK’s Department for Environment, Food and Rural Affairs, would enable the true costs of our environment to be reflected in decisions—undoubtedly tipping the balance in favour of safeguarding and enhancing biodiversity.

The threat posed by climate change is serious and will affect our ecosystems in far-reaching and complex ways. But we have choices about the things we do to cope with these changes. If we make the right choices, not only will biodiversity sit centre stage in our decision making, but the true value of our ecosystem services will also be reflected in decisions. In many cases, if we choose the right way to cope with climate change, we will succeed in safeguarding or even enhancing the diversity of life around us.

Professor Robert Watson is Chief Scientific Advisor at the Department for Environment, Food and Rural Affairs(Defra) in the UK. He previously served as Chief Scientist and Senior Advisor for Sustainable Development at the World Bank and has held senior positions at NASA and the White House.